This invention relates to a gas laser device, in which the neighborhood of the gas inlet for feeding its principal discharge portion with gas flow is improved.
Recently a small size and high power high speed axial flow type gas laser using a Root's blower has been developed and utilized for laser working. In order to increase the output power with a small size laser device, it is necessary to increase the gas pressure of the laser medium. For obtaining a stable glow discharge with a high gas pressure, use is made of means for ejecting the laser medium through a nozzle or a slit with a high speed so as to expand it rapidly. This is described e.g. in JP-A-No. 49-122997, JP-A-No. 58-178579, JP-A-No. 60-70786 (corresponding to U.S. Pat. No. 4,622,675 ), etc.
In these prior art techniques using discharge in a high pressure gas there was a problem that laser output fluctuated, e.g. it varied. Fluctuations in laser output mean not only fluctuations of the magnitude of the laser output but also those in intensity distribution. Thus, a prior art laser device had a disadvantage that according to measurement results of the fluctuations by means of a beam analyzer the frequency of the fluctuations was comprised from several tens of Hz to several kHz where components at the neighborhood of 1 kHz were predominant; and that the laser output varied so strongly that the intensity of the fluctuations amounted to about 50% of that of the laser beam without fluctuations.